"As tenants move out of the building the landlord corp. is selling off the units "

first: get your facts straight! it does not work this way! no one can sell any units unless the building has already legally been converted to a coop or condo! which requires permission from the Attorney General: here's a thought: go read their Coop/Condo Conversion Handbookhttp://www.oag.state.ny.us/ online.